WO2018083896A1

WO2018083896A1 - Semiconductor element, semiconductor laser, and method for manufacturing semiconductor element

Info

Publication number: WO2018083896A1
Application number: PCT/JP2017/033534
Authority: WO
Inventors: 雅洋村山
Original assignee: ソニーセミコンダクタソリューションズ株式会社
Priority date: 2016-11-01
Filing date: 2017-09-15
Publication date: 2018-05-11
Also published as: US11876349B2; US20190393679A1; JP7107849B2; CN109923743A; CN109923743B; JPWO2018083896A1; US11121524B2; US20210376571A1; DE112017005516T5

Abstract

[Problem] The present invention addresses the problem of providing: a semiconductor element wherein electrical connection between a transparent conductive layer and a semiconductor layer can be sufficiently ensured; a semiconductor laser; and a method for manufacturing the semiconductor element. [Solution] A semiconductor element relating to the present technology is provided with a first semiconductor layer, a second semiconductor layer, an active layer, and a transparent conductive layer. The first semiconductor layer has a first conductivity type, and has a stripe-shaped ridge that is formed on the surface. When the width of a ridge surface, on which the transparent conductive layer is formed, said width being in the direction orthogonal to the extending direction of the ridge, is set as a first width, and a transparent conductive layer surface on the ridge side, said width being in the above-mentioned direction, is set as a second width, the second width is 0.99-1.0 times the first width. When the transparent conductive layer surface on the reverse side of the ridge, said width being in the above-mentioned direction, is set as a third width, the third width is 0.96-1.0 times the second width, and in the range of the third width, the transparent conductive layer has a uniform thickness within a range of 90-110 %.

Description

Semiconductor device, semiconductor laser, and manufacturing method of semiconductor device

This technology relates to the technology of semiconductor elements such as semiconductor lasers.

A semiconductor laser is a semiconductor element that amplifies recombination light emission by stimulated emission and emits laser light, and emits laser light with a narrow emission angle and strong intensity. This semiconductor laser is applied to optical communication, an optical pickup for an optical disc, a laser printer, and the like, and further improvement of optical output and reduction of power consumption are desired.

In a semiconductor laser, a current confinement structure is used to inject current into a predetermined region of an active layer sandwiched between a p-type semiconductor layer and an n-type semiconductor layer. The current confinement structure can be realized by forming a striped ridge in the p-type semiconductor layer or the n-type semiconductor layer. A conductive material such as ITO (IndiumＩＴＯTin Oxide) is laminated on the ridge, and the electrode and the semiconductor layer are electrically connected.

For example, Patent Documents 1 and 2 disclose a process flow of a semiconductor laser using a transparent conductive layer. In these process flows, after a resist is laminated on the ridge, the resist on the ridge is removed, and a transparent conductive layer is formed on the ridge using the resist as a mask.

Further, Patent Document 3 discloses a semiconductor laser that uses a transparent conductive layer etched into a waveguide shape as a part of a clad layer. Here, it is mentioned as a simple point in the process that only the transparent conductive layer is processed into a waveguide shape and the p-type layer is not processed.

JP 2011-014891 A JP2015-167263A JP 2004-289157 A

However, in the process flow as described in Patent Document 1 or 2, it is difficult to form the transparent conductive layer up to the ridge end, and the device voltage rise or non-uniformity due to the contact area between the transparent conductive layer and the semiconductor layer being reduced. Current injection may occur. Further, the structure described in Patent Document 3 cannot provide a sufficient lateral light confinement effect.

In view of the circumstances as described above, an object of the present technology is to provide a semiconductor element, a semiconductor laser, and a method for manufacturing the semiconductor element that can sufficiently ensure electrical connection between the transparent conductive layer and the semiconductor layer. .

In order to achieve the above object, a semiconductor element according to an embodiment of the present technology includes a first semiconductor layer, a second semiconductor layer, an active layer, and a transparent conductive layer.
The first semiconductor layer has a first conductivity type, and a striped ridge is formed on the surface.
The second semiconductor layer has a second conductivity type.
The active layer is provided between the first semiconductor layer and the second semiconductor layer.
The transparent conductive layer is made of a transparent conductive material and is formed on the ridge.
The width of the surface of the ridge on which the transparent conductive layer is formed is defined as the first width, and the width of the surface of the transparent conductive layer on the ridge side is defined as the second width. The second width is not less than 0.99 times and not more than 1.0 times the first width,
When the width of the transparent conductive layer opposite to the ridge in the direction is the third width, the third width is 0.96 to 1.0 times the second width. ,
The transparent conductive layer is uniform within a range of 90% to 110% in thickness within the range of the third width.

According to the above configuration, the transparent conductive layer is formed with a uniform thickness on almost the entire surface of the first semiconductor layer in the ridge. Accordingly, the contact area between the transparent conductive layer and the first semiconductor layer in the ridge can be increased, and the voltage of the semiconductor element can be reduced. Further, current can be uniformly injected from the entire upper surface of the ridge, and non-uniform injection of carriers into the active layer can be suppressed, so that non-uniform light emission spread can be suppressed.

The semiconductor element is made of a conductive material, and further includes a pad electrode in contact with the transparent conductive layer,
The pad electrode may include an intermediate layer formed at a joint portion between the pad electrode and the transparent conductive layer, in which constituent elements of the pad electrode and the transparent conductive layer are fused.

According to this configuration, the adhesion between the pad electrode and the transparent conductive layer can be improved by the intermediate layer.

The semiconductor element is made of a metal material, and further includes a metal electrode formed on the transparent conductive layer,
The metal electrode may include an intermediate layer formed at a joint portion between the metal electrode and the transparent conductive layer, in which respective constituent elements of the metal electrode and the transparent conductive layer are fused.

According to this configuration, the adhesion between the metal electrode and the transparent conductive layer can be improved by the intermediate layer.

If the width of the metal electrode on the transparent conductive layer side in the direction is the fourth width, the fourth width may be 0.99 times or more and 1.0 times or less the third width. Good.

In order to achieve the above object, a semiconductor laser according to an embodiment of the present technology includes a first semiconductor layer, a second semiconductor layer, an active layer, and a transparent conductive layer.
The first semiconductor layer has a first conductivity type, and a striped ridge is formed on the surface.
The second semiconductor layer has a second conductivity type.
The active layer is provided between the first semiconductor layer and the second semiconductor layer.
The transparent conductive layer is made of a transparent conductive material and is formed on the ridge.
The width of the surface of the ridge on which the transparent conductive layer is formed is defined as the first width, and the width of the surface of the transparent conductive layer on the ridge side is defined as the second width. The second width is not less than 0.99 times and not more than 1.0 times the first width,
When the width of the transparent conductive layer opposite to the ridge in the direction is the third width, the third width is 0.96 to 1.0 times the second width. ,
The transparent conductive layer is uniform within a range of 90% to 110% in thickness within the range of the third width.

In order to achieve the above object, a method of manufacturing a semiconductor device according to an aspect of the present technology includes a first semiconductor layer having a first conductivity type, a second semiconductor layer having a second conductivity type, and the first semiconductor layer. A laminate including a semiconductor layer and an active layer provided between the second semiconductor layers is prepared.
A transparent conductive layer made of a transparent conductive material is formed on the first semiconductor layer.
A mask structure processed into a stripe shape is formed on the transparent conductive layer.
Using the mask structure as an etching mask, at least a part of the transparent conductive layer and the first semiconductor layer is removed by etching.

According to this manufacturing method, since the transparent conductive layer is etched using the mask structure, it is possible to form the transparent conductive layer with a uniform thickness on almost the entire surface of the first semiconductor layer in the ridge.

The mask structure may be made of a dielectric.

In the step of forming the mask structure, a dielectric layer made of a dielectric is formed on the transparent conductive layer, a photoresist is formed on the dielectric layer, the photoresist is patterned in a stripe shape, and the photo The dielectric layer may be etched using a resist as an etching mask.

The mask structure may be made of metal.

In the step of forming the mask structure, a photoresist is formed on the transparent conductive layer, the photoresist is patterned into a shape having a stripe-shaped opening, and a metal layer is formed on the transparent conductive layer and the photoresist. The photoresist and the metal layer formed on the photoresist may be removed.

In the step of forming the mask structure, a metal layer is formed on the transparent conductive layer, a photoresist is formed on the metal, the photoresist is patterned in a stripe shape, and the metal is formed using the photoresist as an etching mask. The layer may be etched.

After the step of removing at least a part of the transparent conductive layer and the first semiconductor layer by etching, a pad electrode in contact with the transparent conductive layer is formed, and a heat treatment is performed at the joint between the pad electrode and the transparent conductive layer. An intermediate layer in which the constituent elements of the pad electrode and the transparent conductive layer are fused may be formed.

After forming the metal layer on the transparent conductive layer, an intermediate layer in which the constituent elements of the metal layer and the transparent conductive layer are fused is formed at the joint between the metal layer and the transparent conductive layer by heat treatment. May be.

As described above, according to the present technology, it is possible to provide a semiconductor element, a semiconductor laser, and a method for manufacturing a semiconductor element that can sufficiently ensure electrical connection between the transparent conductive layer and the semiconductor layer. Note that the effects described here are not necessarily limited, and may be any of the effects described in the present disclosure.

It is a perspective view of a semiconductor device concerning a 1st embodiment of this art. It is a top view of the semiconductor element. It is sectional drawing of the same semiconductor element. It is a schematic diagram which shows the shape of the transparent conductive layer with which the semiconductor element is provided. It is a schematic diagram which shows the manufacturing process of the same semiconductor element. It is a schematic diagram which shows the manufacturing process of the same semiconductor element. It is a schematic diagram which shows the manufacturing process of the same semiconductor element. It is a schematic diagram which shows the manufacturing process of the same semiconductor element. It is sectional drawing of the semiconductor element which concerns on the 2nd Embodiment of this technique. It is a schematic diagram which shows the shape of the p electrode with which the semiconductor element is provided. It is a schematic diagram which shows the 1st manufacturing process of the same semiconductor element. It is a schematic diagram which shows the 1st manufacturing process of the same semiconductor element. It is a schematic diagram which shows the 1st manufacturing process of the same semiconductor element. It is a schematic diagram which shows the 2nd manufacturing process of the same semiconductor element. It is a schematic diagram which shows the 2nd manufacturing process of the same semiconductor element. It is a schematic diagram which shows the 2nd manufacturing process of the same semiconductor element. It is a schematic diagram which shows the 2nd manufacturing process of the same semiconductor element.

(First embodiment)
A semiconductor device according to the first embodiment of the present technology will be described.

[Structure of semiconductor element]
FIG. 1 is a schematic perspective view showing a semiconductor element 100 according to the first embodiment. FIG. 2 is a plan view thereof. 3 is a cross-sectional view taken along the line CC in FIG. The semiconductor element 100 is a ridge type semiconductor laser having a ridge 151 in a p type conductive layer. The semiconductor element 100 is not limited to a semiconductor laser, and may be an SLD (Super Luminescent Diode), an LED (light emitting diode), or other semiconductor elements.

As shown in FIG. 3, the semiconductor element 100 includes an n-type layer 101, a p-type layer 102, an active layer 103, a transparent conductive layer 104, a dielectric layer 105, and a pad electrode 106. The n-type layer 101, the active layer 103, and the p-type layer 102 are stacked in this order, and the p-type layer 102 forms a striped ridge 151. 1 and 2, the pad electrode 106 and the dielectric layer 105 are not shown. As shown in FIG. 2, the semiconductor element 100 includes a light emitting end face 152 and a rear end face 153 that is an end face opposite to the light emitting end face 152.

As shown in FIG. 2, the ridge 151 is linearly formed from the rear end face 153 to the light emitting end face 152. Hereinafter, the direction in which the ridge 151 extends is defined as the Y direction. Note that the ridge 151 does not necessarily have to be linear, and may be curved.

The n-type layer 101 is made of a group III-V nitride semiconductor such as AlN, GaN, AlGaN, AlInGaN, or InN, and specifically, In _y Al _z Ga _1-yz N (0 ≦ y, 0 ≦ z). , Y + z ≦ 1) or Al _x Ga _1-x N (0 <x <1) or the like is preferable. The constituent material of the n-type layer 101 is doped with an n-type impurity such as Si or Ge, and has an n-type conductivity type. The n-type layer 101 can be formed on a substrate (not shown) made of sapphire, silicon, ZnO, GaAs, GaN, InGaN, AlInGaN, AlGaN, AlN, InN, or the like.

The p-type layer 102 forms a current confinement structure. Specifically, the structure of the ridge 151 is configured such that the current injection region from the p-type layer 102 to the active layer 103 is narrowed. As a result, an optical waveguide along the extending direction (Y direction) of the ridge 151 is formed near the ridge 151 in the active layer 103.

The p-type layer 102 is made of a group III-V nitride semiconductor such as AlN, GaN, AlGaN, AlInGaN, or InN. Specifically, In _y Al _z Ga _1-yz N (0 ≦ y, 0 ≦ z, A gallium nitride compound semiconductor such as y + z ≦ 1) or Al _x Ga _1-x N (0 <x <1) is preferable. The constituent material of the p-type layer 102 is doped with a p-type impurity such as Mg or Zn and has a p-type conductivity type.

The active layer 103 is provided between the n-type layer 101 and the p-type layer 102. The material of the active layer 103 is not particularly limited, but the emission color of the semiconductor element 100 varies depending on the material of the active layer 103. For example, when the active layer 103 is made of AlInGaP, red light having an emission wavelength of 550 to 900 nm (practical range of 630 to 680 nm) is generated. When the active layer 103 is made of AlInGaN, blue-violet to green light having an emission wavelength of 400 to 1000 nm (practical range of 400 to 550 nm) is generated.

In addition, as the material of the active layer 103, AlGaN (emission wavelength ultraviolet region to 400 nm), AlGaAs (emission wavelength 750 to 850 nm, infrared region), InGaAs (emission wavelength 800 to 980 nm, infrared region), InGaAsP (emission wavelength 1.2 to 1.6 μm, infrared region) and the like.

The active layer 103 has a smaller band gap than the surrounding layers (n-type layer 101 and p-type layer 102) and forms a quantum well. When a current is applied between the p-type layer 102 and the n-type layer 101, electrons existing in the conduction band (CB) recombine with holes in the valence band (VB) through the band gap of the quantum well. Emits light.

The transparent conductive layer 104 is formed on the ridge 151 and electrically connects the pad electrode 106 and the p-type layer 102. The transparent conductive layer 104 is made of a light-transmitting conductive material such as ITO (Indium Tin Oxide), ZnO, or IGZO (Indium Gallium Zinc Oxide). Among these, ITO is particularly suitable in terms of ohmic contact to the p-type nitride semiconductor and light absorption. Details of the transparent conductive layer 104 will be described later.

The dielectric layer 105 is formed on the p-type layer 102 and on the side surface of the ridge 151, and insulates the pad electrode 106 and the p-type layer 102. The material of the dielectric layer 105 is not particularly limited, but a material having a refractive index smaller than that of the p-type layer 102 is suitable for efficiently confining light in the ridge 151, and for example, SiO ₂ can be used.

The pad electrode 106 is formed on the transparent conductive layer 104 and the dielectric layer 105 so as to cover the ridge 151. The pad electrode 106 is made of metal. The pad electrode 106 may be composed of a plurality of types of materials. For example, when the transparent conductive layer 104 is made of an oxide, the adhesiveness between the pad electrode 106 and the transparent conductive layer 104 can be improved by using a material that easily forms an oxide such as Ti, Ni, or Al for the portion in contact with the transparent conductive layer 104. Can be improved. For example, the pad electrode 106 can have a laminated structure of Ti / Pt / Au.

As shown in FIG. 3, an intermediate layer 106 a is formed on the pad electrode 106. The intermediate layer 106 a is a layer in which the constituent elements of the transparent conductive layer 104 and the pad electrode 106 are fused. For example, when the transparent conductive layer 104 is made of ITO and the pad electrode 106 is made of Ti / Pt / A, the intermediate layer 106a has a structure in which In, Sn, O, and Ti are mixed. The adhesion between the transparent conductive layer 104 and the pad electrode 106 can be improved by the intermediate layer 106a.

As shown in FIG. 2, a low reflection mirror film 154 is provided on the light emitting end face 152, and a high reflection mirror film 155 is provided on the rear end face 153 on the opposite side.

When a current is applied between the p-type layer 102 and the n-type layer 101, spontaneous emission light is generated in the active layer 103 in the vicinity of the rear end face 153. Spontaneous emission light is amplified by stimulated emission while traveling through the optical waveguide toward the light exit end face 152. Of the spontaneous emission light, the light traveling toward the rear end face 153 is reflected by the high reflection mirror film 155 and amplified while traveling toward the light exit end face 152. The amplified light is emitted from the light emission end face 152 through the low reflection mirror film 154. 1 and 2 show the emitted light L of the semiconductor element 100. FIG.

Note that a low reflection mirror film may be provided on the rear end face 153 instead of the high reflection mirror film 155. In this case, the emitted light is emitted from both ends of the semiconductor element 100.

The semiconductor element 100 can be used as a semiconductor laser, but can also be used as an amplifier for amplifying light generated by another light source. In this case, an antireflection film is provided in place of the high reflection mirror film 155. Light generated by another light source enters the optical waveguide through the antireflective film and is amplified while traveling through the optical waveguide.

[About transparent conductive layer]
The transparent conductive layer 104 included in the semiconductor element 100 has a predetermined shape. FIG. 4 is a schematic diagram showing the shape of the transparent conductive layer 104.

As shown in the figure, the width of the upper surface of the p-type layer 102 in the ridge 151 in the direction (X direction) orthogonal to the extending direction (Y direction) of the ridge 151 is D1, and the p-type layer 102 of the transparent conductive layer 104 is formed. The width in the X direction of the surface on the side is defined as a width D2, and the width in the X direction on the surface opposite to the p-type layer 102 is defined as D3.

At this time, D1, D2, and D3 have a relationship represented by the following [Formula 1] and [Formula 2].

0.99 × D1 ≦ D2 ≦ D1 [Formula 1]
0.96 × D2 ≦ D3 ≦ D2 [Formula 2]

Furthermore, within the range of D3, the thickness (Z direction) of the transparent conductive layer 104 is uniform in the range of 90% to 110%.

Thus, the transparent conductive layer 104 is laminated with a uniform thickness on almost the entire surface of the p-type layer 102 in the ridge 151. Such a shape of the transparent conductive layer 104 can be realized by a manufacturing method described later.

Thereby, the contact area between the transparent conductive layer 104 and the p-type layer 102 in the ridge 151 can be increased, and the voltage of the semiconductor element 100 can be lowered. Further, current can be uniformly injected from the entire upper surface of the ridge 151, and non-uniform injection of carriers into the active layer 103 can be suppressed, so that non-uniform light emission spread can be suppressed.

The semiconductor element 100 has the above configuration. In the above description, the ridge 151 is formed in the p-type layer 102. However, the p-type layer 102, the active layer 103, and the n-type layer 101 are stacked in this order, and a ridge is formed in the n-type layer 101. Also good.

[Method for Manufacturing Semiconductor Device]
A method for manufacturing the semiconductor element 100 will be described. 5 to 8 are schematic views showing a manufacturing process of the semiconductor element 100. FIG.

As shown in FIG. 5A, a transparent conductive layer 104 is formed on a p-type layer 102 of a laminate in which an n-type layer 101, an active layer 103, and a p-type layer 102 are laminated. The transparent conductive layer 104 can be formed by a method such as vapor deposition, sputtering, or plasma CVD (chemical vapor deposition). Annealing treatment may be performed after the formation of the transparent conductive layer 104. Thereby, good ohmic characteristics for the p-type layer 102 can be realized.

Subsequently, a dielectric layer 156 is formed on the transparent conductive layer 104 as shown in FIG. The type of the dielectric layer 156 is not particularly limited, but SiO ₂ is preferable because it is easy to form and process. The dielectric layer 156 can be formed by a method such as vapor deposition, sputtering, or plasma CVD.

Subsequently, a photoresist is formed on the dielectric layer 156 and patterned to form a photoresist R as shown in FIG. The photoresist R is patterned into a stripe shape extending along the Y direction.

Subsequently, the dielectric layer 156 is etched using the photoresist R as a mask, and the dielectric layer 156 is processed into a stripe shape as shown in FIG. Etching can be dry etching or wet etching. For the etchant, for example, a fluorine-based gas can be used.

Subsequently, the photoresist R is removed as shown in FIG.

Subsequently, as shown in FIG. 6C, the transparent conductive layer 104 is etched using the dielectric layer 156 processed into a stripe shape as a mask, and the transparent conductive layer 104 is processed into a stripe shape. As the etching, dry etching or wet etching can be used, but dry etching is preferable from the viewpoint of controlling the stripe width and flatness of the processed side surface. For example, a chlorine-based gas can be used for the etchant.

Subsequently, as shown in FIG. 7A, at least a part of the p-type layer 102 is etched using the dielectric layer 156 and the transparent conductive layer 104 processed into a stripe shape as a mask, thereby forming a ridge 151. For example, a chlorine-based gas can be used for the etchant. This step may be performed separately from the etching of the transparent conductive layer 104 (FIG. 6C), or may be performed at once. By forming the ridge 151 by this method, the transparent conductive layer 104 can be formed on the upper surface of the ridge 151 with a uniform thickness, and the contact area between the transparent conductive layer 104 and the p-type layer 102 can be increased.

Subsequently, as shown in FIG. 7B, the dielectric layer 105 is formed on the p-type layer 102, the transparent conductive layer 104, and the dielectric layer 156.

Subsequently, as shown in FIG. 7C, the dielectric layer 105 on the ridge 151 is removed, and the transparent conductive layer 104 is exposed.

Subsequently, as shown in FIG. 8, a pad electrode 106 is formed so as to cover the entire ridge 151.

Subsequently, an intermediate layer 106a is formed as shown in FIG. The intermediate layer 106a can be formed by mixing the constituent elements of the transparent conductive layer 104 and the pad electrode 106 by heat treatment.

The semiconductor element 100 can be manufactured as described above. In this manufacturing method, the transparent conductive layer 104 can be formed with a uniform thickness on almost the entire surface of the p-type layer 102 in the ridge 151.

(Second Embodiment)
A semiconductor device according to a second embodiment of the present technology will be described.

[Structure of semiconductor element]
FIG. 9 is a plan view of a semiconductor element 200 according to the second embodiment. The semiconductor element 200 is different from the semiconductor element 100 according to the first embodiment in that a p-electrode 201 is provided. Since other configurations are the same as those of the semiconductor element 100, the same reference numerals are given and description thereof is omitted.

The p electrode 201 is provided between the transparent conductive layer 104 and the pad electrode 106. The p electrode 201 is made of metal. Further, the p-electrode 201 may be composed of a plurality of types of materials. For example, in the case where the transparent conductive layer 104 is made of an oxide, the adhesion between the p electrode 201 and the transparent conductive layer 104 can be improved by using a material that easily forms an oxide such as Ti, Ni, or Al for the portion in contact with the transparent conductive layer 104. Can be improved. For example, the p-electrode 201 can have a laminated structure of Ti / Pt / Au.

As shown in FIG. 9, an intermediate layer 201 a is formed on the p-electrode 201. The intermediate layer 201a is a layer in which the constituent elements of the transparent conductive layer 104 and the p-electrode 201 are fused. For example, when the transparent conductive layer 104 is made of ITO and the p-electrode 201 is made of Ti / Pt / A, the intermediate layer 201a has a mixed crystal structure of In, Sn, O, and Ti. The adhesion between the transparent conductive layer 104 and the p-electrode 201 can be improved by the intermediate layer 201a.

FIG. 10 is a schematic diagram showing the shape of the p-electrode 201. As shown in the figure, the width of the surface on the transparent conductive layer 104 side of the p-electrode 201 in the direction (X direction) orthogonal to the extending direction (Y direction) of the ridge 151 is D4. D1, D2 and D3 are the same as in the first embodiment.

At this time, D3 and D4 have the relationship represented by the following [Formula 3].

0.99 × D3 ≦ D4 ≦ 1.0 × D3 [Formula 3]

The semiconductor element 200 has the above configuration. In the above description, the ridge 151 is formed in the p-type layer 102. However, the p-type layer 102, the active layer 103, and the n-type layer 101 are stacked in this order, and a ridge is formed in the n-type layer 101. Also good. In this case, an n electrode is provided in place of the p electrode 201. An intermediate layer in which the transparent conductive layer and the constituent elements of the n electrode are fused may also be provided in the n electrode.

[Manufacturing Method 1 of Semiconductor Element]
A manufacturing method 1 of the semiconductor element 200 will be described. 11 to 13 are schematic views showing a manufacturing process of the semiconductor element 200.

As shown in FIG. 11A, a transparent conductive layer 104 is formed on a p-type layer 102 of a laminate in which an n-type layer 101, an active layer 103, and a p-type layer 102 are laminated. The transparent conductive layer 104 can be formed by a method such as vapor deposition, sputtering, or plasma CVD (chemical vapor deposition). Annealing treatment may be performed after the formation of the transparent conductive layer 104. Thereby, good ohmic characteristics for the p-type layer 102 can be realized.

Subsequently, a photoresist is formed on the transparent conductive layer 104 and patterned to form a photoresist R as shown in FIG. The photoresist R has a stripe-shaped opening extending along the Y direction.

Subsequently, as shown in FIG. 11C, a p-electrode 201 is formed on the photoresist R and the transparent conductive layer 104.

Subsequently, as shown in FIG. 12A, the photoresist R is removed. As a result, the p-electrode 201 formed on the photoresist R is also removed, and a striped p-electrode 201 is formed on the transparent conductive layer 104.

Subsequently, as shown in FIG. 12B, an intermediate layer 201a is formed. The intermediate layer 201a can be formed by mixing the constituent elements of the transparent conductive layer 104 and the p-electrode 201 by heat treatment.

Subsequently, as shown in FIG. 12C, the transparent conductive layer 104 is etched using the p-electrode 201 processed into a stripe shape as a mask, and the transparent conductive layer 104 is processed into a stripe shape. As the etching, dry etching or wet etching can be used, but dry etching is preferable from the viewpoint of controlling the stripe width and flatness of the processed side surface. For example, a chlorine-based gas can be used for the etchant.

Subsequently, as shown in FIG. 13A, at least a part of the p-type layer 102 is etched using the p-electrode 201 and the transparent conductive layer 104 processed into stripes as a mask to form a ridge 151. For example, a chlorine-based gas can be used for the etchant. This step may be performed separately from the etching of the transparent conductive layer 104 (FIG. 12C), or may be performed at once. By forming the ridge 151 by this method, the transparent conductive layer 104 can be formed on the upper surface of the ridge 151 with a uniform thickness, and the contact area between the transparent conductive layer 104 and the p-type layer 102 can be increased.

Subsequently, as shown in FIG. 13B, a dielectric layer 105 is formed on the p-type layer 102, the transparent conductive layer 104, and the p-electrode 201.

Subsequently, as shown in FIG. 13C, the dielectric layer 105 on the ridge 151 is removed, and the p-electrode 201 is exposed.

Subsequently, as shown in FIG. 9, a pad electrode 106 is formed so as to cover the entire ridge 151.

The semiconductor element 200 can be manufactured as described above. In this manufacturing method, the transparent conductive layer 104 can be formed with a uniform thickness on almost the entire surface of the p-type layer 102 in the ridge 151.

[Semiconductor Element Manufacturing Method 2]
A method 2 for manufacturing the semiconductor element 200 will be described. 14 to 17 are schematic views showing a manufacturing process of the semiconductor element 200. FIG.

As shown in FIG. 14A, a transparent conductive layer 104 is formed on a p-type layer 102 of a laminate in which an n-type layer 101, an active layer 103, and a p-type layer 102 are laminated. The transparent conductive layer 104 can be formed by a method such as vapor deposition, sputtering, or plasma CVD (chemical vapor deposition). Annealing treatment may be performed after the formation of the transparent conductive layer 104. Thereby, good ohmic characteristics for the p-type layer 102 can be realized.

Subsequently, as shown in FIG. 14B, a p-electrode 201 is formed on the transparent conductive layer 104.

Subsequently, as shown in FIG. 14C, an intermediate layer 201a is formed. The intermediate layer 201a can be formed by mixing the constituent elements of the transparent conductive layer 104 and the p-electrode 201 by heat treatment.

Subsequently, a photoresist is formed on the p-electrode 201 and patterned to form a photoresist R as shown in FIG. The photoresist R is patterned into a stripe shape extending along the Y direction.

Subsequently, the p-electrode 201 is etched using the photoresist R as a mask, and the p-electrode 201 is processed into a stripe shape as shown in FIG. Etching can be dry etching or wet etching.

Subsequently, as shown in FIG. 15C, the photoresist R is removed.

Subsequently, as shown in FIG. 16A, the transparent conductive layer 104 is etched using the p-electrode 201 processed into a stripe shape as a mask, and the transparent conductive layer 104 is processed into a stripe shape. As the etching, dry etching or wet etching can be used, but dry etching is preferable from the viewpoint of controlling the stripe width and flatness of the processed side surface. For example, a chlorine-based gas can be used for the etchant.

Subsequently, as shown in FIG. 16B, at least a part of the p-type layer 102 is etched using the p-electrode 201 and the transparent conductive layer 104 processed in a stripe shape as a mask, thereby forming a ridge 151. For example, a chlorine-based gas can be used for the etchant. This step may be performed separately from the etching of the transparent conductive layer 104 (FIG. 16A) or may be performed in a lump. By forming the ridge 151 by this method, the transparent conductive layer 104 can be formed on the upper surface of the ridge 151 with a uniform thickness, and the contact area between the transparent conductive layer 104 and the p-type layer 102 can be increased.

Subsequently, as shown in FIG. 16C, a dielectric layer 105 is formed on the p-type layer 102, the transparent conductive layer 104, and the p-electrode 201.

Subsequently, as shown in FIG. 17, the dielectric layer 105 on the ridge 151 is removed, and the p-electrode 201 is exposed.

(About display devices)
The semiconductor elements according to the first and second embodiments of the present technology can be suitably used as a light source of a display device such as a raster scan projector.

In addition, this technique can also take the following structures.
(1)
A first semiconductor layer having a first conductivity type and having a striped ridge formed on the surface;
A second semiconductor layer having a second conductivity type;
An active layer provided between the first semiconductor layer and the second semiconductor layer;
A transparent conductive layer made of a transparent conductive material and formed on the ridge,
The width of the surface of the ridge on which the transparent conductive layer is formed is defined as the first width, and the width of the surface of the transparent conductive layer on the ridge side is defined as the second width. The second width is not less than 0.99 times and not more than 1.0 times the first width,
When the width of the transparent conductive layer opposite to the ridge in the direction is the third width, the third width is 0.96 to 1.0 times the second width. ,
The transparent conductive layer is uniform within a range of 90% to 110% in thickness within the range of the third width.

(2)
The semiconductor element according to (1) above,
A pad electrode made of a conductive material and in contact with the transparent conductive layer;
The said pad electrode is formed in the junction part of the said pad electrode and the said transparent conductive layer, and has an intermediate | middle layer which each component element of the said pad electrode and the said transparent conductive layer united.

(3)
The semiconductor element according to (1) above,
A metal electrode made of a metal material and further formed on the transparent conductive layer,
The said metal electrode is formed in the junction part of the said metal electrode and the said transparent conductive layer, and has an intermediate | middle layer which each element of the said metal electrode and the said transparent conductive layer united.

(4)
The semiconductor element according to (3) above,
When the width of the surface of the metal electrode on the transparent conductive layer side in the direction is the fourth width, the fourth width is 0.99 times to 1.0 times the third width. Semiconductor element .

(5)
A first semiconductor layer having a first conductivity type and having a striped ridge formed on the surface;
A second semiconductor layer having a second conductivity type;
An active layer provided between the first semiconductor layer and the second semiconductor layer;
A transparent conductive layer made of a transparent conductive material and formed on the ridge,
The width of the surface of the ridge on which the transparent conductive layer is formed is defined as the first width, and the width of the surface of the transparent conductive layer on the ridge side is defined as the second width. The second width is not less than 0.99 times and not more than 1.0 times the first width,
When the width of the transparent conductive layer opposite to the ridge in the direction is the third width, the third width is 0.96 to 1.0 times the second width. ,
The transparent conductive layer is uniform within a range of 90% to 110% in thickness within the range of the third width. Semiconductor laser.

(6)
A laminate comprising a first semiconductor layer having a first conductivity type, a second semiconductor layer having a second conductivity type, and an active layer provided between the first semiconductor layer and the second semiconductor layer Prepare
Forming a transparent conductive layer made of a transparent conductive material on the first semiconductor layer;
A mask structure processed into a stripe shape is formed on the transparent conductive layer,
A method for manufacturing a semiconductor device, wherein at least a part of the transparent conductive layer and the first semiconductor layer is removed by etching using the mask structure as an etching mask.

(7)
A method for manufacturing a semiconductor device according to (6) above,
The mask structure is made of a dielectric material.

(8)
A method for manufacturing a semiconductor device according to (7) above,
In the step of forming the mask structure, a dielectric layer made of a dielectric is formed on the transparent conductive layer, a photoresist is formed on the dielectric layer, the photoresist is patterned in a stripe shape, and the photo A method for manufacturing a semiconductor device, comprising etching the dielectric layer using a resist as an etching mask.

(9)
A method for manufacturing a semiconductor device according to (6) above,
The mask structure is made of metal.

(10)
A method for manufacturing a semiconductor device according to (9) above,
In the step of forming the mask structure, a photoresist is formed on the transparent conductive layer, the photoresist is patterned into a shape having a stripe-shaped opening, and a metal layer is formed on the transparent conductive layer and the photoresist. And removing the photoresist and the metal layer formed on the photoresist.

(11)
A method for manufacturing a semiconductor device according to (9) above,
In the step of forming the mask structure, a metal layer is formed on the transparent conductive layer, a photoresist is formed on the metal, the photoresist is patterned in a stripe shape, and the metal is formed using the photoresist as an etching mask. A method of manufacturing a semiconductor device, wherein a layer is etched.

(12)
A method of manufacturing a semiconductor device according to (8) above,
After the step of removing at least a part of the transparent conductive layer and the first semiconductor layer by etching, a pad electrode in contact with the transparent conductive layer is formed, and a heat treatment is performed at the joint between the pad electrode and the transparent conductive layer. A method for manufacturing a semiconductor device, comprising forming an intermediate layer in which constituent elements of the pad electrode and the transparent conductive layer are fused.

(13)
A method for manufacturing a semiconductor element according to (9) or (10) above,
After forming the metal layer on the transparent conductive layer, an intermediate layer in which the constituent elements of the metal layer and the transparent conductive layer are fused is formed at the joint between the metal layer and the transparent conductive layer by heat treatment. A method for manufacturing a semiconductor device.

DESCRIPTION OF SYMBOLS 100 ... Semiconductor element 101 ... N-type layer 102 ... P-type layer 103 ... Active layer 104 ... Transparent conductive layer 105 ... Dielectric layer 106 ... Pad electrode 106a ... Intermediate layer 151 ... Ridge 200 ... Semiconductor element 201 ... P electrode 201a ... Intermediate layer

Claims

A first semiconductor layer having a first conductivity type and having a striped ridge formed on the surface;
A second semiconductor layer having a second conductivity type;
An active layer provided between the first semiconductor layer and the second semiconductor layer;
A transparent conductive layer made of a transparent conductive material and formed on the ridge,
The width of the surface of the ridge on which the transparent conductive layer is formed is a width in the direction perpendicular to the extending direction of the ridge, and the width of the surface of the transparent conductive layer on the ridge side is the second width. The second width is not less than 0.99 times and not more than 1.0 times the first width,
When the width of the surface of the transparent conductive layer opposite to the ridge is the third width, the third width is 0.96 times or more and 1.0 times or less of the second width. ,
The transparent conductive layer is uniform in a thickness range of 90% to 110% within the range of the third width.
The semiconductor device according to claim 1,
A pad electrode made of a conductive material and in contact with the transparent conductive layer;
The said pad electrode is formed in the junction part of the said pad electrode and the said transparent conductive layer, and has an intermediate | middle layer which each element of the said pad electrode and the said transparent conductive layer united.
The semiconductor device according to claim 1,
A metal electrode made of a metal material and formed on the transparent conductive layer;
The said metal electrode is formed in the junction part of the said metal electrode and the said transparent conductive layer, and has an intermediate | middle layer which each component element of the said metal electrode and the said transparent conductive layer united.
The semiconductor device according to claim 3,
When the width in the direction of the surface of the metal electrode on the transparent conductive layer side is a fourth width, the fourth width is 0.99 times to 1.0 times the third width. Semiconductor element .
A first semiconductor layer having a first conductivity type and having a striped ridge formed on the surface;
A second semiconductor layer having a second conductivity type;
An active layer provided between the first semiconductor layer and the second semiconductor layer;
A transparent conductive layer made of a transparent conductive material and formed on the ridge,
The width of the surface of the ridge on which the transparent conductive layer is formed is a width in the direction perpendicular to the extending direction of the ridge, and the width of the surface of the transparent conductive layer on the ridge side is the second width. The second width is not less than 0.99 times and not more than 1.0 times the first width,
When the width of the surface of the transparent conductive layer opposite to the ridge is the third width, the third width is 0.96 times or more and 1.0 times or less of the second width. ,
The transparent conductive layer is uniform within a range of 90% to 110% in thickness within the range of the third width. Semiconductor laser.
A laminate comprising a first semiconductor layer having a first conductivity type, a second semiconductor layer having a second conductivity type, and an active layer provided between the first semiconductor layer and the second semiconductor layer Prepare
Forming a transparent conductive layer made of a transparent conductive material on the first semiconductor layer;
Forming a mask structure processed into a stripe shape on the transparent conductive layer;
A method for manufacturing a semiconductor device, wherein at least a part of the transparent conductive layer and the first semiconductor layer is removed by etching using the mask structure as an etching mask.
A method of manufacturing a semiconductor device according to claim 6,
The mask structure is made of a dielectric material.
A method of manufacturing a semiconductor device according to claim 7,
In the step of forming the mask structure, a dielectric layer made of a dielectric is formed on the transparent conductive layer, a photoresist is formed on the dielectric layer, the photoresist is patterned in a stripe shape, and the photo A method of manufacturing a semiconductor device, comprising etching the dielectric layer using a resist as an etching mask.
It is a manufacturing method of the optical element according to claim 6,
The mask structure is made of metal.
A method of manufacturing a semiconductor device according to claim 9,
In the step of forming the mask structure, a photoresist is formed on the transparent conductive layer, the photoresist is patterned into a shape having a stripe-shaped opening, and a metal layer is formed on the transparent conductive layer and the photoresist. And removing the photoresist and the metal layer formed on the photoresist.
A method of manufacturing a semiconductor device according to claim 9,
In the step of forming the mask structure, a metal layer is formed on the transparent conductive layer, a photoresist is formed on the metal, the photoresist is patterned in a stripe shape, and the metal is used as an etching mask. A method of manufacturing a semiconductor device, wherein a layer is etched.
A method of manufacturing a semiconductor device according to claim 8,
After the step of removing at least a part of the transparent conductive layer and the first semiconductor layer by etching, a pad electrode in contact with the transparent conductive layer is formed, and a heat treatment is performed at the joint between the pad electrode and the transparent conductive layer. A method for manufacturing a semiconductor device, comprising forming an intermediate layer in which constituent elements of the pad electrode and the transparent conductive layer are fused.
It is a manufacturing method of the semiconductor device according to claim 9 or 10,
After the metal layer is formed on the transparent conductive layer, an intermediate layer in which the constituent elements of the metal layer and the transparent conductive layer are fused is formed at the joint between the metal layer and the transparent conductive layer by heat treatment. A method for manufacturing a semiconductor device.